A U.N. nuclear team arrived in Tehran early Sunday for a mission expected to focus on Iran's alleged attempt to develop nuclear weapons. The U.N. nuclear agency delegation includes two senior weapons experts — Jacques Baute of France and Neville Whiting of South Africa — suggesting that Iran may be prepared to address some issues related to the allegations. The delegation from the International Atomic Energy Agency is led by Deputy Director General Herman Nackaerts, who is in charge of the Iran nuclear file. Also on the team is Rafael Grossi, IAEA chief Yukiya Amano's right-hand man. In unusually blunt comments ahead of his arrival in Tehran, Nackaerts urged Iran to work with his mission on probing the allegations about Iran's alleged attempts to develop nuclear weapons, reflecting the importance the IAEA is attaching to the issue. Tehran has refused to discuss the alleged weapons experiments for three years, saying they are based on "fabricated documents" provided by a "few arrogant countries" a phrase authorities in Iran often use to refer to the United States and its allies.